(3,3) is the point in which the 2 lines intersect
The slope intercept is equal to the rise/run.
So lets say to get from one point to the other, you go down 2 units and go right 3 units.
Since you went down it is a -2. If you had gone up 2 units, then it would be a positive 2.
Since you went to the right, it is a positive 3. If you had gone left 3 units, then it would be -3.
-2/3
2.21 x 10^17 and the answer is 2.21e+17